Yahoo Autos Mysterious aurora-like phenomenon 'STEVE' appears during strongest solar storm for more than half a decade
A bizarre, aurora-like phenomenon known as STEVE made several appearances across the United States and parts of the United Kingdom last week, after a powerful solar storm slammed into Earth without warning.
STEVE, also known as a "strong thermal emission velocity enhancement," is a rare phenomenon that was officially discovered in 2016. During STEVE, a long, thick ribbon of light — usually white, purple or green in color — appears to hang in the sky for up to an hour. Although it looks very similar to auroras, or northern lights, and often appears at the same time, STEVE is not an aurora.
On March 23, a surprise coronal mass ejection (CME) — a gargantuan, fast-moving blob of plasma and magnetic field released from the sun — erupted from a massive hole in the sun that was wider than 20 Earths. Astronomers did not see the stealthy storm coming because it traveled much slower than normal CMEs and was therefore almost impossible to track. The resulting geomagnetic storm on Earth was the most powerful for six years and triggered spectacular auroras across the globe.
Related: Blood-red aurora transforms into 'STEVE' before stargazer's eyes
